This is a test version of Biostars. For the public version, visit https://www.biostars.org.
MagicBLAST only using one thread

I am using the -num_threads option for magicBLAST and running from a linux shell. However only one thread is used (tried on 2 machines). The file.fa is only 20MB.

magicblast -query file.fa -db nt -num_threads 16 -out out.sam -no_unaligned

Any ideas?

magicblast

No big deal of a help, but, previously I had some similar issues with other tools and the problem was dependencies needed to do parallel processing.

I have no issue with multithreading using other apps eg bwa, bowtie2 etc use mutithreads OK. Wondering if if could be due to the large size of the nt database (120GB)

Ok. Then you can just test using a smaller db, and tell us if it worked

1 answer

After 20 min was using multiple threads. I presume there is a stage when magicBLAST only uses a single thread when starting. NB I also reduced num_theads to 4 but havent tested if that has anything to do with it (24 thread machine)

Log in to answer this question.